The role of expectancy in fear reduction

Abstract

Systematic desensitization was compared with a highly credible expectancy modification procedure and a waiting list control condition in the modification of fear of snakes in a clinical population. Subjects' expected anxiety and self-efficacy were measured during pre- and posttreatment assessment periods, and credibility and predicted posttreatment anxiety levels were assessed during the first treatment session. There were no significant differences in improvement between the two treated groups, although both showed significantly greater improvement than was found in waiting list control subjects. Expected anxiety was highly correlated with behavioral and self-report measures of fear at pre- and posttreatment assessment. In addition, unlike credibility ratings, predictions of posttreatment fear levels made during the first treatment session were highly correlated with measures of actual posttreatment fear. Exceptionally high correlations between expected fear and self-efficacy suggest that these are a single construct. The results support the hypothesis that the intensity of experienced fear varies as a function of the expectancy for its occurrence. They also raise questions about the construct validity of self-efficacy measures.